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Articles 1651 - 1680 of 2720
Full-Text Articles in Chemistry
Cellular Distribution Of Activity For Three Enzymes With Maltose Binding Protein As Fusion Partner And The Structural Implications, Özde F. Ütkür, Berna Sariyar Akbulut, Amable Hortaçsu
Cellular Distribution Of Activity For Three Enzymes With Maltose Binding Protein As Fusion Partner And The Structural Implications, Özde F. Ütkür, Berna Sariyar Akbulut, Amable Hortaçsu
Turkish Journal of Chemistry
The bacterial SEC pathway is commonly used for secretion of heterologous proteins in E. coli by fusing them to transported proteins to facilitate downstream processing. While some proteins are translocated very efficiently, some reside in the cytoplasm. In this work, maltose binding protein (MBP) was fused to 3 cytoplamic enzymes from Thermus thermophilus (serine protease, 251 residues; glucose isomerase, 381 residues; pullulanase, 718 residues) to study the protein transport from the cytoplasm by quantifying the distribution of activities in different cellular compartments. Pullulanase activity was harvested exclusively in the periplasm; however, glucose isomerase activity was harvested exclusively in the cytoplasm. …
Study Of Catalytic Activities Of Nanostructure Copper And Cobalt Supported Zsm-5 Catalysts For Conversion Of Volatile Organic Compounds, Aligholi Niaei, Dariush Salari, Seyed Ali Hosseini
Study Of Catalytic Activities Of Nanostructure Copper And Cobalt Supported Zsm-5 Catalysts For Conversion Of Volatile Organic Compounds, Aligholi Niaei, Dariush Salari, Seyed Ali Hosseini
Turkish Journal of Chemistry
This paper reports the comparison of the activities of nanostructure Cu-ZSM-5 and Co-ZSM-5 catalysts for conversion of ethyl acetate and toluene and deals with the relationship between activity and structure of catalysts. The catalysts were characterized by ICP-AES, XPS, EDX, XRD, SEM, and TEM techniques. Catalytic studies were carried out under atmospheric pressure and in a temperature range of 200-500 °C. Cu-ZSM-5 catalysts showed better activity than Co-ZSM-5, revealing higher activity of copper cations. The higher activity was ascribed to higher electro-negativity, smaller cation radius, good distribution, and specific coordination of copper cations inside Cu-ZSM-5 catalysts. The activity of catalysts …
Synthesis, Characterization, And Application Of Nanoporous Materials Based On Silicon- Or Halogen-Containing Spiroketal And Spirothioketal Polymers, Hamada H. Abdel-Razik
Synthesis, Characterization, And Application Of Nanoporous Materials Based On Silicon- Or Halogen-Containing Spiroketal And Spirothioketal Polymers, Hamada H. Abdel-Razik
Turkish Journal of Chemistry
Organic microporous materials based on silicon-containing spiroketal and spirothioketal polymers were synthesized via a 1,3-dioxol-forming polymerization reaction between 1,1a,4,4a,5,5a,8, 8a-octahydro-2,3,6,7-tetra(trimethylsilyl)-9,10-anthraquinone and different types of polyol or polythiol. These silicon-containing polymers were subjected to bromination to yield bromine-containing polymers. The structures of the prepared polymers were confirmed by NMR spectroscopy and molecular mass measurements. Nitrogen adsorption/desorption isotherms of the prepared polymers showed that a large amount of nitrogen was adsorbed at low relative pressure, indicating microporosity. These polymers have BET surface areas in the range of 505-830 m^2 g^{-1}. These polymers were determined to be useful for pervaporation separation of phenol/water …
Characterization Of Chitosan In Acetic Acid: Rheological And Thermal Studies, Esam A. El-Hafian, Elham S. Elgannoudi, Azizah Mainal, Abdul Haamid Bin Yahaya
Characterization Of Chitosan In Acetic Acid: Rheological And Thermal Studies, Esam A. El-Hafian, Elham S. Elgannoudi, Azizah Mainal, Abdul Haamid Bin Yahaya
Turkish Journal of Chemistry
This study examined the influence of temperature, concentration, shearing time, and storage time on the rheological properties, i.e. the dynamic viscosity and shear stress, as a function of shear rate of chitosan solubilized in weakly acid solutions. The results showed that shear thinning behavior (pseudoplastic non-Newtonian behavior) was pronounced at temperatures from 20 to 50 °C, but was more remarkable at lower temperature. In addition, the activation energy value derived from ln \eta vs. 1/T data was found to be 20.86 kJ mol^{-1}. When the effect of concentration was studied, the shear thinning behavior was pronounced at all concentrations. The …
Synthesis Of Some Pyridazine Derivatives Carrying Urea, Thiourea, And Sulfonamide Moieties And Their Antimicrobial Activity, Deni̇z S. Doğruer, Şölen Urlu, Ti̇jen Önkol, Berri̇n Özçeli̇k, M. Fethi̇ Şahi̇n
Synthesis Of Some Pyridazine Derivatives Carrying Urea, Thiourea, And Sulfonamide Moieties And Their Antimicrobial Activity, Deni̇z S. Doğruer, Şölen Urlu, Ti̇jen Önkol, Berri̇n Özçeli̇k, M. Fethi̇ Şahi̇n
Turkish Journal of Chemistry
Some pyridazine derivatives carrying urea, thiourea, and sulfonamide groups were synthesized and evaluated for their antimicrobial activity against gram-positive and gram-negative bacteria, and fungi by using broth microdilution. The structures of these new compounds were confirmed by ^1H-NMR, mass spectrum, and elemental analysis. The synthesized compounds exhibited generally promising inhibitory activity against S. aureus (MIC ranging from 2 to 4 \mu g/mL) and E. coli (MIC ranging from 4 to 16 \mu g/mL). Moreover, all compounds showed antifungal activity against both C. albicans and C. parapsilosis, with a MIC value of 8 \mu g/mL.
Influence Of Alcl_3 On The Optical Properties Of New Synthesized 3-Armed Poly(Methyl Methacrylate) Films, Adnan Kurt
Influence Of Alcl_3 On The Optical Properties Of New Synthesized 3-Armed Poly(Methyl Methacrylate) Films, Adnan Kurt
Turkish Journal of Chemistry
Three-armed poly(methyl methacrylate)[PMMA] was synthesized by atom transfer radical polymerization at 100 °C using benzene-1,3,5-triyl tris(4-(bromomethyl) benzoate as 3-armed initiator and a cuprous(I) bromide/2,2'-bipyridine catalytic system. The characterization of PMMA was confirmed by FT-IR, ^1H-NMR, GPC, DSC, and TGA techniques. Optical absorption measurements were also studied by UV-VIS technique. Transmittance and reflectance measured in the wavelength range 300-700 nm were used to calculate the optical constants. The changes in dispersion and Urbach parameters were investigated as a function of AlCl_3 content. The wide band tails increased in width and the optical energy gap decreased from 2.39 to 1.28 eV as …
Synthesis And Characterization Of New Optically Active Polyamides Containing 2-(4-Nitro-1,3-Dioxoisoindolin-2-Yl)Succinic Acid And Aromatic Diamines Via Direct Polycondensation, Khalil Faghihi, Morteza Absalar, Mohsen Hajibeygi
Synthesis And Characterization Of New Optically Active Polyamides Containing 2-(4-Nitro-1,3-Dioxoisoindolin-2-Yl)Succinic Acid And Aromatic Diamines Via Direct Polycondensation, Khalil Faghihi, Morteza Absalar, Mohsen Hajibeygi
Turkish Journal of Chemistry
A new class of optically active polyamides (PAs) (6a-e) having 4-nitro-1,3-dioxoisoindolin-2-yl pendent groups were prepared by direct polycondensation reaction of 2-(4-nitro-1,3-dioxoisoindolin-2-yl) succinic acid (4) with various aromatic diamines in a medium consisting of triphenyl phosphite, calcium chloride, pyridine, and N-methyl-2-pyrrolidone. The resulting new polymers were obtained in high yields with inherent viscosities ranging between 0.32 and 0.48 dL/g, and were characterized by elemental analysis, FT-IR spectroscopy, specific rotation, solubility tests, and thermogravimetric analysis techniques (TGA and DTG). Bulky pendent groups of the polymer chains disturb interchain and intrachain interactions and make these PAs readily soluble in polar organic solvents such …
Multichannel Spectrophotometry For Analysis Of Organophosphate Paraoxon In Beverages, Miroslav Pohanka, Jana Zdarova Karasova, Kamil Kuca, Jiri Pikula
Multichannel Spectrophotometry For Analysis Of Organophosphate Paraoxon In Beverages, Miroslav Pohanka, Jana Zdarova Karasova, Kamil Kuca, Jiri Pikula
Turkish Journal of Chemistry
Multichannel spectrophotometry was performed to assay for paraoxon in spiked beverages. A 96-well microplate was used for this purpose. The measuring protocol was based on inhibition of the enzyme acetylcholinesterase by paraoxon that resulted in decreased or no reaction of the enzyme product thiocholine with Ellman's reagent (5,5'-dithiobis [2-nitrobenzoic acid]). The above assay was practically tested using spiked drinking water, mineral water, and coffee. Analytical parameters such as the limit of detection, time, and sample size consumption were adequate. The limit of detection for beverages ranged from 32 to 48 ppb corresponding to 0.32-0.48 ng of paraoxon in absolute values. …
Synthesis And Uranyl Ion Adsorption Study Of Cross-Linked Allyl Propionate-Maleic Anhydride-Styrene Terpolymer, Elchin Akperov, Abel Maharramov, Oktay Akperov
Synthesis And Uranyl Ion Adsorption Study Of Cross-Linked Allyl Propionate-Maleic Anhydride-Styrene Terpolymer, Elchin Akperov, Abel Maharramov, Oktay Akperov
Turkish Journal of Chemistry
Allyl propionate-maleic anhydride-styren terpolymer has been modified with glycerin in order to prepare a new cross-linked functional polymer sorbent. The synthesized cross-linked polymer sorbent has a network structure and contains carboxylic acid, carbonyl, hydroxy, and ester groups, all of which are capable ofinteracting with metal ions. The sorption behavior of UO_2^{2+} ions under optimum sorption conditions was determined. The sorption properties of the sorbent were determined under different conditions by varying of the pH of medium, the sorbent weight, and the initial concentration of uranyl ions. The maximum experimental sorption capacity of the sorbent for uranyl ions was measured as …
Radical Scavenging Potential Of Compounds Isolated From Vitex Agnus-Castus, . Azizuddin, Talat Makhmoor, Muhammad Iqbal Choudhary
Radical Scavenging Potential Of Compounds Isolated From Vitex Agnus-Castus, . Azizuddin, Talat Makhmoor, Muhammad Iqbal Choudhary
Turkish Journal of Chemistry
Nine secondary metabolites-artemetin (1), casticin (2), 3-hydroxy-5,6,7,4'-tetramethoxy flavone U(3), penduletin (4), p-hydroxybenzoic acid (5), methyl 3,4-dihydroxybenzoate (6), methyl isovanillate (7), vanillic acid (8), and 3,4-dihydroxybenzoic acid (9)-were isolated from a folkloric medicinal plant, Vitex agnus-castus. The structures of compounds 1-9 were identified using spectroscopic techniques. Compound 7 was isolated for the first time from this plant. These compounds were screened for their antioxidant activity. Compounds 6 and 9 exhibited significant activity against the DPPH free radical.
Template Synthesis And Characterization Of 16-Membered Octaazamacrocyclic Complexes: A Photoelectron Spectroscopic Study, Abul Kalam, Vishnu Tripathi, Shekhar Srivastava, Yogesh Pandey, Anil Kumar, Alok Gupta, Sharat Srivastava, Ankoor Purohit
Template Synthesis And Characterization Of 16-Membered Octaazamacrocyclic Complexes: A Photoelectron Spectroscopic Study, Abul Kalam, Vishnu Tripathi, Shekhar Srivastava, Yogesh Pandey, Anil Kumar, Alok Gupta, Sharat Srivastava, Ankoor Purohit
Turkish Journal of Chemistry
A novel series of complexes of the type [MLX_2] where M= Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); X= C^- or NO_3^- were synthesized by template condensation of hydrazine hydrate, acetaldehyde, 2,4-pentanedione, and thiocarbohydrazide in the presence of divalent metal salt in methanolic solution. The complexes were characterized with the help of elemental analysis, conductance measurements, magnetic measurements, electronic, NMR, XPS, and infrared and far infrared spectral studies. Electronic spectra along with magnetic moments suggest 6-coordinated octahedral geometry for these complexes. The low value of molar conductance indicates them to be non-electrolytes.
Performance Evaluation Of Platinum-Based Catalysts For The Development Of Proton Exchange Membrane Fuel Cells, Abdul Sattar Ali Khan, Riaz Ahmed, Muhammad Latif Mirza
Performance Evaluation Of Platinum-Based Catalysts For The Development Of Proton Exchange Membrane Fuel Cells, Abdul Sattar Ali Khan, Riaz Ahmed, Muhammad Latif Mirza
Turkish Journal of Chemistry
Platinum-based catalysts are considered the most efficient catalysts for triggering electrochemical reactions in proton exchange membrane (PEM) fuel cells. In the present study, commercial catalysts containing 10% and 30% Pt supported on Vulcan XC-72 carbon were studied to assess their performance in PEM fuel cells. Both catalysts consisted of Pt particles of almost the same size. The utility of these catalysts in PEM fuel cells was studied by finding the real surface area and rate of electro-oxidation of methanol in 0.5 M H_2SO_4 by using cyclic voltammetry. The methanol oxidation reaction was used for characterization of catalysts of PEM fuel …
Synthesis And Antimicrobial Activity Of N-Alkyl Substituted P-Methyl (E)-3- And 4-Azachalconium Bromides, Nuretti̇n Yayli, Gülbi̇n Misir, Nuran Yayli, Ahmet Yaşar, Emi̇ne Demi̇r, Zi̇hni̇ Demi̇rbağ
Synthesis And Antimicrobial Activity Of N-Alkyl Substituted P-Methyl (E)-3- And 4-Azachalconium Bromides, Nuretti̇n Yayli, Gülbi̇n Misir, Nuran Yayli, Ahmet Yaşar, Emi̇ne Demi̇r, Zi̇hni̇ Demi̇rbağ
Turkish Journal of Chemistry
Twenty new N-alkyl substituted p-methyl (E)-3- and 4-azachalcones (1a-j, 2a-j){3-[(1E)-3-(4-methylp-henyl)-3- oxoprop-1-en-1-yl]-1-alkyl (C_{5-12,_{14-15) pyridinium bromides (1a-j) and 4-[(1E)-3-(4-methylp-henyl)-3-oxoprop-1-en-1-yl]-1-alkyl (C_{5-12,_{14-15) pyridinium bromides (2a-j)} were synthesized and tested for antimicrobial activities against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Enterococcus faecalis, Proteus vulgaris, and Escherichia coli. They showed good antimicrobial activity especially against the gram-positive bacteria tested with minimal inhibitory concentration (MIC) values less than 4.7 \mu g/mL in most cases. The optimum length of the alkyl chain for better and broader activity is situated in the range of 8-12 carbon atoms in the series of compounds 1a-j, 2a-j. The non-alkylated compounds 1-2 were …
Inclusion And Release Of Theophylline From Chitosan Based Microparticles, Niculina Popa, Ovidiu Novac, Lenuta Profire, Doina Hritcu, Marcel Ionel Popa
Inclusion And Release Of Theophylline From Chitosan Based Microparticles, Niculina Popa, Ovidiu Novac, Lenuta Profire, Doina Hritcu, Marcel Ionel Popa
Turkish Journal of Chemistry
Chitosan (CS) based microparticles for controlled release of theophylline (THP) were obtained by ionic gelation. The microparticles were characterized by laser diffraction analysis (particle size), scanning electron microscopy (SEM), FTIR spectroscopy, and thermogravimetric analysis. The average diameter of the CS-THP microparticles was 182 \mu m. The FTIR spectra confirmed that new hydrogen bonds had formed between the carbonylic group belonging to THP and the amino group of CS, while the thermogravimetric analysis showed a modified stability in the obtained particles and confirmed the presence of an interaction between the drug and CS. The THP release process was monitored for up …
Synthesis And Characterization Of Non-Symmetric Tetradentate Complexes Of Zn(Ii), Co(Ii), And Cu(Ii), Maryam Lashanizadegan, Shima Seraj
Synthesis And Characterization Of Non-Symmetric Tetradentate Complexes Of Zn(Ii), Co(Ii), And Cu(Ii), Maryam Lashanizadegan, Shima Seraj
Turkish Journal of Chemistry
The non-symmetrical tetradentate Schiff-base H_2L was obtained using the half-unit N-(1-hydroxy-2-acetophenone)-1-amino- 2-phenyleneimine (HL) with 2-hydroxyl-1-naphthaldehyde. ZnL, CoL, and CuL complexes were prepared and characterized by ^1H-NMR, IR, electronic, and atomic absorption spectra. The single crystal X-ray structure of CuL was determined. Crystal data for CuL are triclinic space group P-1, a = 8.3933 (17) Å, b = 11.197 (2) Å, c = 13.381 (3) Å, \alpha = 95.29 (3)°, \beta = 94.37 (3)°, \gamma = 95.82 (3)°, and z = 2.
Stabilizing Cyclacene Molecules, Muthana Shanshal
Stabilizing Cyclacene Molecules, Muthana Shanshal
Turkish Journal of Chemistry
It is shown that introducing a single methylene group into each trannulene ring of a cyclacene molecule compels the formation of a non-bonded molecular orbital, NBMO, in the ring. The union of both trannulenes conforms to a first order perturbation change in the total energy according to Dewar's PMO theory. The NBMO coefficients can be calculated then according to Coulson's pairing theorem. The PMO calculated new HOMO-LUMO energies of the cyclacene indicate the relative stabilization of the singlet over the triplet state of the cyclacene. The results are confirmed by the DFT calculation of differently substituted bis, methylene cyclacenes. The …
Simultaneous Determination Of Cu(Ii) And Pd(Ii) As 4-Phenylpiperazinecarbodithioate Complex Using H-Point Standard Addition Method And Derivative Spectrophotometry, Varinder Kaur, Ashok Kumar Malik, Neelam Verma
Simultaneous Determination Of Cu(Ii) And Pd(Ii) As 4-Phenylpiperazinecarbodithioate Complex Using H-Point Standard Addition Method And Derivative Spectrophotometry, Varinder Kaur, Ashok Kumar Malik, Neelam Verma
Turkish Journal of Chemistry
A new, simple, inexpensive, and sensitive method for the simultaneous spectrophotometric determination of Cu(II) and Pd(II) by H-point standard addition method and derivative spectrophotometry is described. 4- Phenylpiperazinecarbodithioate (PPDTC) in an anionic micellar solution of SLS was used as a reagent at pH 4. The experimental parameters, such as pH, type of surfactant, concentration of reagent, and surfactant used, were optimized to minimize the errors. The linear ranges of the method were 0.1-10 and 0.1-11 \mu g mL^{-1} for Cu(II) and Pd(II), respectively. The results of applying H-point standard addition and fourth derivative spectrophotometry showed that Cu(II) and Pd(II) can …
Direct Reductive Amination Of Carbonyl Compounds Using Sodium Borohydride-Silica Chloride, Heshmatollah Alinezhad, Mahmood Tajbakhsh, Neda Hamidi
Direct Reductive Amination Of Carbonyl Compounds Using Sodium Borohydride-Silica Chloride, Heshmatollah Alinezhad, Mahmood Tajbakhsh, Neda Hamidi
Turkish Journal of Chemistry
A simple and convenient procedure for reductive amination of aldehydes and ketones using sodium borohydride in the presence of silica chloride as an active, inexpensive, recoverable, and recyclable catalyst is described. The reactions were carried out with equimolar amounts of amine and carbonyl compound using silica chloride-sodium borohydride in THF at room temperature.
Picolyl Substituted N-Heterocyclic Carbene/Palladium Catalyzed Heck Reactions, Murat Yi̇ği̇t, Beyhan Yi̇ği̇t, İsmai̇l Özdemi̇r, Engi̇n Çeti̇nkaya
Picolyl Substituted N-Heterocyclic Carbene/Palladium Catalyzed Heck Reactions, Murat Yi̇ği̇t, Beyhan Yi̇ği̇t, İsmai̇l Özdemi̇r, Engi̇n Çeti̇nkaya
Turkish Journal of Chemistry
Novel 1,3-dialkylimidazolinium and 1,3- dialkyltetrahydropyrimidinium hexafluorophosphate salts as N-heterocyclic carbene precursors were prepared by reacting N,N'-dialkylethandiamine or N,N'-dialkylpropandiamine, triethyl orthoformate, and ammonium hexafluorophosphate. The salts were characterized spectroscopically and tested in homogeneous Heck reactions.
Synthesis, Characterization, Crystal Structures, And Antibacterial Activity Of Some New 1-(3,4,5-Trimethoxybenzoyl)-3-Aryl Thioureasreas, Aamer Saeed, Rasheed Ahmad Khera, Naeem Abbas, Muhammad Latif, Imran Sajid, Ulrich Flörke
Synthesis, Characterization, Crystal Structures, And Antibacterial Activity Of Some New 1-(3,4,5-Trimethoxybenzoyl)-3-Aryl Thioureasreas, Aamer Saeed, Rasheed Ahmad Khera, Naeem Abbas, Muhammad Latif, Imran Sajid, Ulrich Flörke
Turkish Journal of Chemistry
Synthesis of some novel 1-(3,4,5-trimethoxy)benzoyl-3- arylthiourea derivatives (1a-o) was accomplished in 2 steps. The synthetic route involves the reaction of 1-(3,4,5-trimethoxy)benzoyl chloride with potassium thiocyanate in 1:1 molar ratio in acetone to afford the corresponding isothiocyante followed by treatment with suitably substituted anilines. The structures of the products were established by elemental analyses, IR, ^1H- and ^{13}C-NMR, and mass spectroscopy and for 1b and 1m from single crystal X-ray diffraction data. All of the synthesized compounds (1a-o) were screened for antibacterial activity against gram positive and gram negative bacterial strains and were found to exhibit low activity towards the tested …
Convenient Synthesis Of Monomeric Steroids From Steroidal Oxalate Dimers Using Flash Vacuum Pyrolysis (Fvp), Lutfun Nahar, Alan Turner, Satyajit Sarker
Convenient Synthesis Of Monomeric Steroids From Steroidal Oxalate Dimers Using Flash Vacuum Pyrolysis (Fvp), Lutfun Nahar, Alan Turner, Satyajit Sarker
Turkish Journal of Chemistry
Flash vacuum pyrolysis (FVP) or thermolysis (FVT), an environmentally friendly method for studying organic reaction mechanisms as well as synthesis, was applied to a series of oxalate dimers (1, 3, 5, 7, 9, 11, 13, and 15) to synthesise monomeric enes, dienes, and a triene (2, 4, 6, 8, 10, 12, 14, and 16). All steroidal monomers were identified by spectroscopic means.
An Efficient Synthesis Of Schiff Bases Containing Benzimidazole Moiety Catalyzed By Transition Metal Nitrates, Akbar Mobinikhaledi, Naser Foroughifar, Mehdi Kalhor
An Efficient Synthesis Of Schiff Bases Containing Benzimidazole Moiety Catalyzed By Transition Metal Nitrates, Akbar Mobinikhaledi, Naser Foroughifar, Mehdi Kalhor
Turkish Journal of Chemistry
A simple and efficient method has been developed for the synthesis of some novel Schiff bases via the reaction of aromatic aldehydes with 2-aminobenzimidazole by using catalytic amount of M(NO_3)_2.xH_2O in an organic solvent at room temperature. Some advantages of this protocol are its very good yields, use of available catalysts, simple workup procedure, and short reaction times.
Asymmetric Synthesis Of 8-O-4'-Neolignan Perseal B, Yamu Xia, Wei Wang, Yinglan Guo, Junfeng Li
Asymmetric Synthesis Of 8-O-4'-Neolignan Perseal B, Yamu Xia, Wei Wang, Yinglan Guo, Junfeng Li
Turkish Journal of Chemistry
Full details of an enantioselective total synthesis of 8-O-4'-neolignan perseal B are presented for the first time. The synthesis was achieved in 8 steps from vanillin and involved the asymmetric dihydroxylation reaction using AD-mix-\alpha to give the key intermedium (1S,2S)-1-(4-(benzyloxy)-3-methoxyphenyl)propane-1,2,3- triol, and the Mitsunobu reaction between phenylpropanoid and vanillin formed perseal B. The synthetic method of perseal B exhibits a new route for 8-O-4'-neolignan.
Synthesis, Characterisation, And Structural Elucidation By Spectral Investigation (Ft-Ir, Multinuclear Nmr, Mass Spectrometry) Of Biologically Active Organotin(Iv) Compounds Containing Germanium, Muhammad Kaleem Khosa, Muhammad Mazhar, Saqib Ali, Sarim Dastgir
Synthesis, Characterisation, And Structural Elucidation By Spectral Investigation (Ft-Ir, Multinuclear Nmr, Mass Spectrometry) Of Biologically Active Organotin(Iv) Compounds Containing Germanium, Muhammad Kaleem Khosa, Muhammad Mazhar, Saqib Ali, Sarim Dastgir
Turkish Journal of Chemistry
A new series of di and tri-organotin(IV) compounds containing germanium with the general formula R_{4-n}SnL_n was synthesised by reaction of 3-triphenylgermanyl-3,3-dimethylpropionic acid with organotin(IV) oxides and organotin(IV) chloride in 2:1 and 1:1 molar ratio, respectively, where R~=~CH_3, C_2H_5, n-C_4H_9, n-C_8H_{17}, and C_6H_5 n = 1 or 2 and L~=~triphenylgermanyl acid anion (GeC_{23} H_{23} O_2^-). These compounds were characterised by elemental analyses, FT-IR, multinuclear NMR (^1H, ^{13}C, ^{119}Sn), and mass spectrometry. The geometry around the tin atom was determined and compared in both solution and solid states. The spectroscopic results indicated that all the diorganotin(IV) compounds containing germanium possess trigonal-bipyramidal structures …
A Theoretical Study Of The Effects Of Polar Substitution On The Activation Barriers For Internal Rotation Around The C-N Bond In P-Substituted Nitrosobenzenes: Comparison Of Dft And Mp2 Calculations, Şafak Özhan Kocakaya, Necmetti̇n Pi̇ri̇nççi̇oğlu
A Theoretical Study Of The Effects Of Polar Substitution On The Activation Barriers For Internal Rotation Around The C-N Bond In P-Substituted Nitrosobenzenes: Comparison Of Dft And Mp2 Calculations, Şafak Özhan Kocakaya, Necmetti̇n Pi̇ri̇nççi̇oğlu
Turkish Journal of Chemistry
The activation barriers for internal rotation around the C-N bond in p-substituted nitrosobenzenes were calculated using the density functional theory (DFT) and second-order Møller-Plesset (MP2) methods with the 6-31+g(d) basis set. The polarisable continuum model (PCM) was used to model the solvent effect. An explicit water molecule was also introduced to form a hydrogen bond with the nitrosogroup and its effect on the barrier was studied by DFT. The barriers were well-correlated with Hammett sigma^+ rather than sigma values, meaning a strong resonance effect. The MP2 method produces better and comparable results with the few available experimental values.
Molecular Recognition Of Aromatic Amines By Coumarin Substituted Azacrown Ether, Hiten Mehta, Harjinder Kaur, Shobhana Menon
Molecular Recognition Of Aromatic Amines By Coumarin Substituted Azacrown Ether, Hiten Mehta, Harjinder Kaur, Shobhana Menon
Turkish Journal of Chemistry
New chromogenic azacrown ether N[7-hydroxy-4-methyl-coumarin-8-methylene]-4-azadibenzo-18-crownether (HMCMADCE) was synthesised through the condensation reaction of 4-azadibenzo-18-crown- 6ether, 4-methyl,7-hydroxy coumarin and formaldehyde was used to investigate its behaviour towards the aromatic amines. All the aromatic primary amines gave specific colours in aqueous medium. The functional group recognition behaviour is further extended to study the estimation of the aromatic primary amine in commercial drug samples. The amines can be estimated in the presence of several functional groups like phenolic-OH, secondary and tertiary aromatic amines as well as aliphatic amines.
Synthesis, Characterization, Antibacterial And Antifungal Evaluation Of Some New Platinum(Ii) Complexes Of 2-Phenylbenzimidazole Ligands, Semra Utku, Mustafa Topal, Ayli̇n Döğen, Mehmet Sami̇ Seri̇n
Synthesis, Characterization, Antibacterial And Antifungal Evaluation Of Some New Platinum(Ii) Complexes Of 2-Phenylbenzimidazole Ligands, Semra Utku, Mustafa Topal, Ayli̇n Döğen, Mehmet Sami̇ Seri̇n
Turkish Journal of Chemistry
A series of platinum(II) complexes of the type [PtL_2Cl_2] 1, [PtL_2I_2] 2, [PtL_2(oxalato)] 3, and [PtL_2(malonato)] 4 (L= 2-phenylbenzimidazole ligands as ``non-leaving groups'') were synthesized and characterized by their elemental analyses, IR, ^1H NMR, and ESI-LC/MS. The in vitro antimicrobial activity of the synthesized compounds has been evaluated by the macrodilution method against gram-positive bacteria, such as Staphylococcus aureus, Bacillus subtilis, and Enterococcus faecalis; gram-negative bacteria, such as Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumonia; and yeast like fungi, such as Candida glabrata and Candida parapsilosis. In general, based on the data obtained in this study, synthesized complexes 1-4 might …
Synthesis And Characterization Of Hybrid Congo Red From Chloro-Functionalized Silsesquioxanes, Ahmet Gültek
Synthesis And Characterization Of Hybrid Congo Red From Chloro-Functionalized Silsesquioxanes, Ahmet Gültek
Turkish Journal of Chemistry
Congo red dye has been bonded to the functionalized octameric polyhedral silsesquioxanes (POSS), which were prepared by hydrolytic condensation of chloro-functionalized organosilicon monomers in the presence of a catalyst. The binding reaction of congo red to the POSS with chloro groups was achieved via the addition of the congo red via NaCl elimination. The structures of POSS with chloro side groups provided an attractive site for binding congo red that not only retains some of its characteristic properties, but also has exceptional hybrid properties possessed by the silica. The dye characteristics of the material were determined by means of UV …
Mannich Base Derivatives Of 3-Hydroxy-6- Methyl-4h-Pyran-4-One With Antimicrobial Activity, Demet Us, Barkin Berk, Eni̇se Ece Gürdal, Ni̇han Ayteki̇n, Zühtü Tanil Kocagöz, Berrak Çağlayan, Işil Kurnaz, Di̇lek Demi̇r Erol
Mannich Base Derivatives Of 3-Hydroxy-6- Methyl-4h-Pyran-4-One With Antimicrobial Activity, Demet Us, Barkin Berk, Eni̇se Ece Gürdal, Ni̇han Ayteki̇n, Zühtü Tanil Kocagöz, Berrak Çağlayan, Işil Kurnaz, Di̇lek Demi̇r Erol
Turkish Journal of Chemistry
A series of 3-hydroxy-6-methyl-2-[(substitutedpiperidine-1-yl) methyl]-4H-pyran-4-one structured compounds were synthesized by reacting 5-hydroxy-2-methyl-4H-pyran-4-one with suitable piperidine derivatives using Mannich reaction conditions. Antibacterial activities of the compounds for E. coli ATCC 25922, S. paratyphi ATCC BAA-1250, S. flexneri ATCC 12022, E. gergoviae ATCC 33426, and M. smegmatis ATCC 14468 were assessed in vitro by the broth dilution method for determination of minimum inhibitory concentration (MIC). In addition, their inhibitory effects over DNA gyrase enzyme were evaluated using a DNA gyrase supercoiling assay. All the synthesized compounds showed a MIC value of either 8 or 16 \mu g/mL for M. smegmatis, whereas minimum …
Electrochemical Properties Of 1-(O-, M-, P-Nitrophenyl)-3-(M-Nitrophenyl)- 5-Phenylformazans And Their Nickel Complexes, Habi̇be Tezcan, Mehmet Levent Aksu
Electrochemical Properties Of 1-(O-, M-, P-Nitrophenyl)-3-(M-Nitrophenyl)- 5-Phenylformazans And Their Nickel Complexes, Habi̇be Tezcan, Mehmet Levent Aksu
Turkish Journal of Chemistry
The electrochemical properties of NO_2 formazans and their Ni(II) complexes were investigated. The investigated formazans included a NO_2 group at the o-, m-, and p-positions of the 1-phenyl ring and at the m-position of the 3-phenyl ring. The oxidation and reduction peak potentials, number of electrons transferred, diffusion coefficient, heterogeneous rate constant, and possible reaction mechanism of the compounds were determined with the use of cyclic voltammetry (CV), ultramicrodisc electrodes (UMEs), and chronoamperometry (CA). The peak potentials (E}_{ox1}) were observed to shift towards more anodic potentials in formazans and more cathodic potentials in their respective Ni complexes compared to unsubstituted …